noun, often attributive
back·​up | \ ˈbak-ˌəp How to pronounce backup (audio) \

Definition of backup

 (Entry 1 of 2)

1a : one that serves as a substitute or support I brought an extra pencil for backup. a backup plan
b : musical accompaniment The tunes include banjo and guitar backup.
c : additional personnel who provide assistance The police officer called for backup.
2 : an accumulation caused by a stoppage in the flow traffic backup
3 : a copy of computer data (such as a file or the contents of a hard drive) I made a backup copy of the file. also : the act or an instance of making a backup

back up

backed up; backing up; backing up

Definition of back up (Entry 2 of 2)

intransitive verb

: to accumulate in a congested state traffic backed up for miles

transitive verb

1 : to move into a position behind (a teammate) in order to assist on a play
3 : to make a copy of (a computer file or data) to protect against accidental loss or corruption Be sure to back up your work. also : to make copies of all the files on (a device) a program that automatically backs up your hard drive

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Synonyms for backup

Synonyms: Noun

bottleneck, jam, jam-up, logjam, snarl, tailback [British], tie-up

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Examples of backup in a Sentence


His role on the team is to be a backup to the regular quarterback. We have an extra radio as a backup in case this one doesn't work. We have an extra radio for backup. He provides backup for the regular quarterback. She sang backup on his CD.
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Recent Examples on the Web: Noun

Wieters went to spring training with a minor league contract and earned a job as a backup to nine-time All-Star Yadier Molina. Brian Stull, The Seattle Times, "Wieters leads Cards over Dodgers 11-7 for 4-game sweep," 11 Apr. 2019 Going into 2018, Murray was best known in the sports world as the backup to Mayfield. Matthew Gutierrez, WSJ, "College Football’s Best Baseball Player," 20 Aug. 2018 As the backup to 2017 Heisman Trophy winner Baker Mayfield last season, Kyler Murray threw for 359 yards and three touchdowns in seven appearances. Peter Dawson, star-telegram, "TCU football's status as a Big 12 contender depends on Kyler Murray's MLB future," 4 June 2018 Guzan was the backup to Revolution coach Brad Friedel at Aston Villa from 2008-10. Dan Mcloone,, "Revolution quickly get back in action against Atlanta," 29 May 2018 Stave participated in rookie minicamp for the Browns this past weekend, serving as the backup to Baker Mayfield. Dan Labbe,, "Browns claim punter Justin Vogel, waive quarterback Joel Stave," 7 May 2018 Role expectation Will immediately start on special teams in covering kicks and serve as backup to Giovani Bernard. Paul Dehner Jr.,, "Bengals' fourth-round pick RB Mark Walton: 'The round don't make nobody'," 28 Apr. 2018 Since being drafted in 2015, Thompson has largely served as a backup to Davis and a situational player in their big-nickel package. Jourdan Rodrigue, charlotteobserver, "6 Carolina Panthers players to watch as spring workouts begin | Charlotte Observer," 16 Apr. 2018 Kaepernick, 30, visited with the Seahawks last May, when Seattle was in the market for a backup to starting quarterback Russell Wilson, but the team decided not to sign him. Matt Bonesteel,, "Seahawks reportedly postpone a Colin Kaepernick workout over protest uncertainty," 12 Apr. 2018

Recent Examples on the Web: Verb

Falk's statements were echoed by Sky Sports Germany reporter Torben Hoffman, who also backed up the idea that Johnson's revelation had jumped the gun somewhat, and that a move to the Bundesliga champions was far from dead and buried., "Bayern Munich 'Still an Option' for Callum Hudson-Odoi as Chelsea Look to Tie Winger Down Long-Term," 6 June 2019 Twenty-nine households were evacuated from Hartford’s Barbour Gardens apartment complex Wednesday night after a plumbing failure caused wastewater to back up in their buildings, city officials said. Rebecca Lurye,, "Sewage backup forces emergency relocations from troubled Hartford apartment complex," 6 June 2019 After data indicated that Houston's business cycle was showing signs of a slowdown in the first months of 2019, the business cycle appears to have picked back up in the three months ending in April. Erin Douglas, Houston Chronicle, "Recent data points to healthy Houston economy: Dallas Fed," 4 June 2019 Smith pleaded guilty and was sentenced last week while inside an ambulance that had been backed up to the loading area at the Hamilton County Courthouse. Kevin Grasha,, "How a 600-pound man ran a drug operation from the bed of Carthage home," 4 June 2019 The action picks right back up with Colton knocking on Cassie's door and asking to talk. Anna Moeslein, Glamour, "The Bachelor Season 23 Finale Recap: Cassie Makes Her Final Decision," 13 Mar. 2019 The service was suspended during WWI in an attempt to conserve funding for the war effort; after the war, only New York and Boston picked it back up again. Popular Mechanics Editors, Popular Mechanics, "12 Geeky Ways to Deliver Mail: U.S. Postal Service Technology Through the Ages," 18 Jan. 2019 Viewers created the #ISupportMollyMcCook hashtag as a way to back up the 28-year-old actress, who first appeared on the season 7 premiere of the series, which also stars Tim Allen and Nancy Travis. Megan Stein, Country Living, "'Last Man Standing' Fans Shut Down Molly McCook's Haters After Recast Drama," 29 Oct. 2018 Deselecting Wow is also in your best interest, as their extra baggage fees (which apply to each leg of your trip) will bring those low prices right back up. Bridget Hallinan, Condé Nast Traveler, "Flight Deal: U.S. to Paris from $331 Round-Trip," 27 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'backup.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of backup


1910, in the meaning defined at sense 1a


1801, in the meaning defined at intransitive sense

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Statistics for backup

Last Updated

9 Jun 2019

Look-up Popularity

Time Traveler for backup

The first known use of backup was in 1801

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More Definitions for backup

back up


Financial Definition of back up

What It Is

A back up is an increase in a security’s price, yield, or spread before issuance.

In other circles, back up means replacing a long-maturity security with a short-maturity security in order to capitalize on short-term interest rates that are higher than long-term interest rates.

How It Works

For example, let’s assume that Company XYZ wants to issue $100 million in 10-year bonds. The yields on bonds of similar quality and risk were about 5% when Company XYZ hired the underwriter to handle the bond issue, but since then the required yields have increased to 7%. This means Company XYZ has to issue the bonds at a bigger discount in order to keep the issue competitive, and thus it will obtain less cash from investors at the time of the sale.

This increase in the cost of issuing the securities is a back up.

Why It Matters

Back ups can be very detrimental to issuers, especially if they are relying on a very specific amount of money to come from the issue, and even more especially if the company’s success hinges on the reinvestment of those funds.

Source: Investing Answers



English Language Learners Definition of backup

: a person or thing that can be used to replace or support another person or thing
: help or support provided by additional people or things
US : a situation in which the flow of something (such as traffic) becomes blocked


back·​up | \ ˈbak-ˌəp How to pronounce backup (audio) \

Kids Definition of backup

: a person who takes the place of or supports another The guard called for a backup.

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More from Merriam-Webster on backup

Rhyming Dictionary: Words that rhyme with backup

Thesaurus: All synonyms and antonyms for backup

Spanish Central: Translation of backup

Nglish: Translation of backup for Spanish Speakers

Britannica English: Translation of backup for Arabic Speakers

Comments on backup

What made you want to look up backup? Please tell us where you read or heard it (including the quote, if possible).


incapable of being surmounted or overcome

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